Fluid Compartments
What percentage of body fluid is found inside cells (ICF)?
65%
What is the average daily water intake and loss in mL?
2,500 mL/day
What is the normal range for sodium in the blood?
135–145 mEq/L
What is the normal pH range of blood?
7.35–7.45
What type of acidosis occurs when ventilation is too slow to eliminate CO₂?
Respiratory acidosis
Name two types of transcellular fluid.
Cerebrospinal fluid, synovial fluid (others: pleural, peritoneal, pericardial, bile, eye humors)
What hormone is released in response to increased blood osmolarity?
Antidiuretic hormone (ADH)
What condition results from sodium levels above 145 mEq/L?
Hypernatremia
What buffer system is most important in extracellular fluid?
Carbonic acid–bicarbonate buffer system
What type of alkalosis results from chronic vomiting?
Metabolic alkalosis
Which electrolyte is most abundant in the intracellular fluid?
Potassium (K⁺)
Why does blood osmolarity increase during dehydration?
Water is lost, leaving solutes more concentrated
What are two causes of hypokalemia?
Chronic vomiting, diarrhea, alkalosis
What happens to pH when CO₂ levels rise in the body?
pH decreases (more acidic)
What is the difference between fully and partially compensated acid-base imbalance?
Fully: pH normal; Partially: pH improving but still abnormal
What separates fluid compartments and allows selective movement of water and solutes?
Semipermeable membranes
What is the term for water loss through skin without sweating?
Cutaneous transpiration
What hormone promotes sodium reabsorption and potassium excretion?
Aldosterone
What organ system is the most powerful long-term regulator of pH?
Urinary (renal) system
What condition results from excess ketone bodies in diabetes or alcoholism?
Metabolic acidosis (ketoacidosis)
What is the ‘catch-all’ category for fluids like cerebrospinal and synovial fluid called?
Transcellular fluid
What are the two sources of water gain in the body?
Metabolic water and preformed water (from food and drink)
What are the effects of hypercalcemia on nerve and muscle cells?
Reduces Na⁺ permeability, inhibits depolarization → weakness, depressed reflexes, arrhythmias
A patient’s ABG shows:
pH = 7.32
PaCO₂ = 50 mmHg
HCO₃⁻ = 26 mEq/L
What type of acid-base imbalance is this, and is it compensated?
Uncompensated respiratory acidosis
pH is low → acidosis
PaCO₂ is high → respiratory cause
HCO₃⁻ is normal → no metabolic compensation yet
What is the role of the respiratory system in compensating for metabolic acidosis?
Increases ventilation to eliminate CO₂ and raise pH